Given the point A(6,3) lies on the graph of g(x), and the point B(6,5) lies on the graph of h(x), where h(x)=(f∘g)(x), the corresponding point that lies on the graph of f(x) must be

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?